如何检查CakePHP 3中是否存在Flash消息？

Question

In Yii (both version) for flash messages we have methods like: hasFlash for checking if a flash message exists beforehand and getFlash to get the content of a specific flash message...

In Yii 1x I would say something like this (whether in the Controller or in a View):

View:

<?php if(Yii::app()->user->hasFlash('success')): ?>
    <div class="alert alert-success">
        <?=Yii::app()->user->getFlash('success'); ?>
    </div>
<?php endif; ?>

Controller:

if($something->happend()) {
    Yii::app()->user->setFlash('success', 'You\'ve done something wonderful.');
    return $this->redirect('/elsewhere');
}

In CakePHP 3 this seems impossible, since the only thing I can do is to set a Flash message:

$this->Flash->set('Welcome, to the real world.', [
    'element' => 'success',
]);

There are no get or has methods for Flash messages, or anything similar that I could find related to FlashComponent and FlashHelper classes.

The other thing about this Flash messages implementation in CakePHP 3 is the way you render and show them to the visitor; you just say the following in your views/layout:

<?= $this->Flash->render(); ?>

That method will actually do the rendering, checking if a flash exists, whatever... and the thing is I need to check if a Flash message is sent/exists, then to do something else within the layout. Now it seems impossible to me or I am not looking in the right direction.

I would note that this is a very strange and bad implementation of Flash messages in CakePHP 3...

Finally, the question:

How can I check if a Flash message exists, whether in a view or in a controller?

Answer 1

You can use key while setting the Flash. see below

$this->Flash->set('Welcome, to the real world.', ['key' => 'alert']);

check by key in render before call

<?php 
if($this->Flash->render('alert')){
    echo $this->Flash->render('alert');
}
?>